Can you expand your insight “to” a person?

Question

For example, in a case where someone already has insight, and they later developed an insight into a certain person, could it be said as,

He expanded his insight to Joe.

Answer 1

The expression expanded his insight sounds really weird and a quick search in COCA shows that such an expression is very rare.

New Oxford American Dictionary suggests that

insight

the capacity to gain an accurate and deep intuitive understanding of a person or thing: this paper is alive with sympathetic insight into Shakespeare.

• an understanding of this kind: the signals would give marine biologists new insights into the behavior of whales.

and this is how you should express it:

He gained a deeper insight into to Joe.

though it is always better to write it this way:

He gained insight into Joe's behavior (or some other attribute of Joe's, as suggested by JIM)

as the word insight is more commonly used to express the idea of gaining an understanding of a particular problem, situation or thing.

insight into the real issue

insight into why Natalie is now moving in a new direction

insight into the market

insight into each child's capabilities

insight into the brain's functioning

insight into both professional and personal characteristics of potential employees